February 28th 1953: Watson and Crick discover DNA structure
On this day in 1953, scientists James D. Watson and Francis Crick discovered the
chemical structure of DNA. They made the discovery of the double helix
structure whilst building a cardboard model of the molecule in their
laboratory at Cambridge University. Their model of DNA was based on an
X-ray diffraction image taken by Rosalind Franklin and the fact that DNA
bases are paired. They first announced their discovery to friends and
it was not formally announced to the wider scientific community until April 25th. Watson, Crick and
Maurice Wilkins were jointly awarded the 1962 Nobel Prize for Physiology
or Medicine for their discoveries. The discovery was a groundbreaking
moment for science, and lay the foundations for the research into DNA
and the investigation of human genetics.
“We have found the secret of life.” - Francis Crick
Sequential information is transferred (or transcribed) residue by residue from DNA to RNA in every cell’s nucleus. The corresponding RNA is then modified to varying degrees, and transported out of the nucleus into the cytoplasm, where the genetic sequence is translated (via ribosomes) to make proteins.
DNA and RNA are nucleic acids, or long polymers made of of singular units calls nucleotides. A unit of three sequential nucleotides in a messenger RNA molecule is called a codon, and each codon codes for a single amino acid in the protein. Proteins are often made up of thousands or hundreds of thousands of amino acids.
The central dogma also states that the process cannot operate in reverse; proteins cannot be used to create RNA or DNA.
The central dogma is the single most important aspect of molecular biology.
In his 1988 autobiography, What Mad Pursuit, Francis Crick wrote about his choice of the word “dogma” and some of the problems it caused him:
I called this idea the “central dogma,” for two reasons, I suspect. I had already used the obvious word “hypothesis" in the sequence hypothesis, and in addition I wanted to suggest that this new assumption was more central and more powerful. … As it turned out, the use of the word dogma caused almost more trouble than it was worth…. Many years later Jacques Monod pointed out to me that I did not appear to understand the correct use of the word dogma, which is a belief that cannot be doubted. I did apprehend this in a vague sort of way but since I thought that all religious beliefs were without foundation, I used the word the way I myself thought about it, not as most of the world does, and simply applied it to a grand hypothesis that, however plausible, had little direct experimental support.
On February 21, 1953, Francis Crick and James Watson discovered the structure of deoxyribonucleic acid (DNA) using unacknowledged photographs and research by their colleague Rosalind Franklin. They had considered many other candidates for the structure, including single and triple strand helices before deciphering the structure. Franklin’s x-ray crystallography (image on right) would provide the missing essential clue they needed to decipher the structure. They would publish a paper that same year describing their discovery, but the significance of the discovery was largely overlooked by the general public for over a year. Today it stands as one of the most remarkable milestones in the history of science.
The word deoxyribonucleic is a compound word formed around the main root word ribose, which arrived in English in 1892 via the German word Ribose which was itself borrowed from the English word of 1880 arabinose, a sugar derived from gum arabic. The word nucleic comes from the Latin word nucleus meaning a kernal around 1700, from the Latin diminutive nucula meaning a little nut. It did not take the meaning of a central characteristic or attribute until 1762. It wasn’t applied to cellular structures for another 70 years around 1862. The -oxy- root comes from the Ancient Greek word οξυς (oxys) meaning sharp or pointed (sharing the earlier common root word that gave the Latin word acer with the same meaning and ultimately the English word acid). The de- prefix is a Latin preposition meaning down from, off or away from, used mainly in English compound words as a privative, meaning that something lacks something.
Queen Elizabeth and Prince Philip made a visit to the Francis Crick Institute on November 9, 2016.
“The institute referred to as ‘The Crick’ is a research institute dedicated to discovering the fundamental biology underlying human health, with the aim of improving the prevention, diagnosis and treatment of human disease.”
me when someone credits James Watson and Francis Crick for the discovery of the double helical structure of DNA like they didn’t steal the credit from Rosalind Franklin because they were angry that a woman was better at science than the two of them combined
You, your joys and your sorrows, your memories and ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules.
sorry, can’t hear you over the awesomeness of my gemini squad
Margaret Fuller (American journalist, critic, and women’s rights advocate)
Diego Velasquez (Spanish painter who was one of the most important painters of the Spanish Golden Age)
Paul Gauguin (His work was influential to the French avant-garde and many modern artists, such as Pablo Picasso and Henri Matisse)
Gustave Courbet (French painter who led the Realist movement, he rejected academic convention and the Romanticism of the previous generation of visual artists)
Daniel Fahrenheit (German physicist best known for inventing the mercury-in-glass thermometer and for developing atemperature scale now named after him.)
Rachel Carson (American marine biologist and conservationist
credited with advancing the global environmental movement.)
Mary Anning (British paleontologist with findings that contributed to important changes in scientific thinking about prehistoric life and the histpry of earth)
Francis Crick (British molecular biologist, biophysicist, andneuroscientist, most noted for being a co-discoverer of the structure of the DNA molecule)
James Maxwell (Scottish scientist in the field of mathematical physics. His most notable achievement was to formulate the classical theory of electromagnetic radiation)
Carl Linnaeus (Swedish botanist, physician, and zoologist, who laid the foundations for the modern biological naming scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology.)
Barbara McClintock (American scientist and cytogeneticist who demonstrated
the notion of genetic recombination by crossing-over and
produced the first genetic map for maize, linking regions of the chromosome to physical traits.)
Peter Higgs (
British theoretical physicist, invented the Higgs mechanism, which predicts the existence of a new particle, the Higgs boson, the detection of which became one of the great goals of physics.)
Robert Mullikan (
American physicist and chemist, primarily responsible for the early development of molecular orbital theory)
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Angelina Jolie even
Chris Evans need
Chris Pratt to?
Queen Victoria (Her reign is known as the Victorian era. It was a period of industrial, cultural, political, scientific, and military change within the United Kingdom, and was marked by a great expansion of the British Empire)
Jurgen Habermas (German sociologist and philosopher
widely recognized as one of the world’s leading intellectuals.)
Jane grant (American journalist and co-founder of The New Yorker who was also the first full-fledged reporter at The New York Times.)
Aloysius Alzheimer (Alzheimer is credited with identifying the first published case of “presenile dementia”, also called Alzheimer’s disease.)
Virginia apgar (American obstetrical anesthesiologist, she introduced
obstetrical considerations to the established field of neonatology and invented the Apgar Score)
Nathaniel chapman (American physician, he was the founding president of the American Medical Association)
Joseph guillotin (French physician and freemason who proposed the use of a device to carry out death penalties in France, as a less painful method of execution. The device was later named the guillotine)
Anne frank (She is one of the most discussed Jewish victims of the Holocaust. Her diary
documents her experiences hiding during the German occupation of the Netherlands in World War II.)
Walt whitman (Whitman is among the most influential poets in the American canon, often called the father of free verse. His work was very controversial in its time. “Oh Captain! My Captain!”)
Sir Arthur Conan Doyle (Scottish writer and physician, most noted for his fictional stories about the detective Sherlock Holmes, which are generally considered milestones in the field of crime fiction.)
Ian Fleming (English author, journalist and naval intelligence officer, best known for his James Bond series of spy novels.)
Thomas Mann (German novelist, short story writer, social critic, philanthropist, essayist, and the 1929 Nobel Prize in Literature laureate.)
The Human Fertilization and Embryology Authority will decide Thursday whether the Francis Crick Institute, a biomedical research facility, will become the first British team to use CRISPR/Cas9 to modify a human embryo. So far, human gene editing has been taboo — but this initiative could be huge for infertility.
Transcript: What one of the problems we have in discussing consciousness scientifically is that consciousness is irreducibly subjective. This is a point that many philosophers have made – Thomas Nagel, John Sorrell, David Chalmers. While I don’t agree with everything they’ve said about consciousness I agree with them on this point that consciousness is what it’s like to be you. If there’s an experiential internal qualitative dimension to any physical system then that is consciousness. And we can’t reduce the experiential side to talk of information processing and neurotransmitters and states of the brain in our case because – and people want to do this. Someone like Francis Crick said famously you’re nothing but a pack of neurons. And that misses the fact that half of the reality we’re talking about is the qualitative experiential side. So when you’re trying to study human consciousness, for instance, by looking at states of the brain, all you can do is correlate experiential changes with changes in brain states. But no matter how tight these correlations become that never gives you license to throw out the first person experiential side. That would be analogous to saying that if you just flipped a coin long enough you would realize it had only one side. And now it’s true you can be committed to talking about just one side. You can say that heads being up is just a case of tails being down. But that doesn’t actually reduce one side of reality to the other.
And to give you a more precise example, we have very strong third person “objective measures” of things like anxiety and fear at this moment. You bring someone into the lab, they say they’re feeling fear. You can scan their brains with fMRI and see that their amygdala response is heightened. You can measure the sweat on their palms and see that there’s an increased galvanic skin response. You can check their blood cortisol and see that its spiking. So these now are considered objective third person measures of fear. But if half the people came into the lab tomorrow and said they were feeling fear and showed none of these signs and they said they were completely calm when their cortisol spiked and when their palms started to sweat, these objective measures would no longer be reliable measures of fear. So the cash value of a change in physiology is still a change in the first person conscious side of things. And we’re inevitably going to rely on people’s subjective reports to understand whether our correlations are accurate. So the hope that we are going to talk about consciousness shorn of any kind of qualitative internal experiential language, I think, is a false one. So we have to understand both sides of it subjective – classically subjective and objective.
I’m not arguing that consciousness is a reality beyond science or beyond the brain or that it floats free of the brain at death. I’m not making any spooky claims about its metaphysics. What I am saying, however, is that the self is an illusion. The sense of being an ego, an I, a thinker of thoughts in addition to the thoughts. An experiencer in addition to the experience. The sense that we all have of riding around inside our heads as a kind of a passenger in the vehicle of the body. That’s where most people start when they think about any of these questions. Most people don’t feel identical to their bodies. They feel like they have bodies. They feel like they’re inside the body. And most people feel like they’re inside their heads. Now that sense of being a subject, a locus of consciousness inside the head is an illusion. It makes no neuro-anatomical sense. There’s no place in the brain for your ego to be hiding. We know that everything you experience – your conscious emotions and thoughts and moods and the impulses that initiate behavior – all of these things are delivered by a myriad of different processes in the brain that are spread out over the whole of the brain. They can be independently erupted. We have a changing system. We are a process and there’s not one unitary self that’s carried through from one moment to the next unchanging. [TRANSCRIPT TRUNCATED]
Directed/Produced by Jonathan Fowler, Elizabeth Rodd, and Dillon Fitton
Documentary: DNA - Secret of Photo 51 (NOVA) [55:00]
The discovery of the “double helix” DNA structure by James Watson, Francis Crick and Maurice Wilkins - which won the Nobel Prize in 1962 - ranks as the single most formidable scientific discovery in modern history. Yet in retrospect, the events are bittersweet, for beneath lies buried a tragic irony: Watson, Crick and Wilkins might never have reached their conclusions (or, at least, reached the conclusions as early as they did) without a massive contribution from a crystallographer and molecular biologist named Rosalind Franklin - a contribution that went publicly uncredited and undocumented. Franklin made the fateful decision to share one of her pivotal X-ray photographs of an inner molecular structure to the deputy director of her lab, Wilkins - who then, without Franklin’s knowledge, casually revealed the image (known as ‘Photograph 51’) to Watson and Crick.
An honest man, armed with all the knowledge available to us now, could only state that in some sense, the origin of life appears at the moment to be almost a miracle, so many are the conditions which would have had to have been satisfied to get it going.
Nobel prize-winning biochemist Dr. Francis Crick in Life Itself: Its Origin and Nature, 1981
Born in 1887 in Vienna, Schrödinger studied physics at the University of Vienna.
He served in the Austrian army in World War I. Then, he resumed his career as a physicist, first as Max Wien’s assistant at the University of Jena.
In 1926 Schrödinger published the first of four famous papers on wave mechanics in which he derived a wave equation for time-independent systems.
Schrödinger coined the term entanglement for the strange quantum connection between intertwined particles and devised the head-scratching thought experiment in which a cat is simultaneously dead and alive. 🐈🎁
Schrödinger shared the 1933 physics Nobel with Paul Dirac for their “discovery of new productive forms of atomic theory.”
In his later years Schrödinger wrote several books. Among the most influential was “What Is Life? The Physical Aspect of the Living Cell” (1944), in which he proposed that life’s genetic information is stored in an aperiodic crystal. The book inspired Francis Crick and James Watson to search for that crystal, DNA.
Dr. Kathy Niakan and her team at the Francis Crick Institute, a biomedical research institute in the United Kingdom, have been given permission from the Human Fertilisation and Embryology Authority to edit our very earliest selves. They’re hoping this will give us “a deeper understanding of the earliest stages of human life“ and help treat a biological problem.
In 1953, English biologist Francis Crick wrote a letter to his 12-year-old son Michael, describing a discovery he and his colleague had recently made.
In the letter, Crick sketches what is now perhaps one of the most famous scientific diagrams in world—the structure of DNA
Michael Crick put that letter up for auction on April 10 with Christie’s in New York City. It sold for $5.3 million to an anonymous buyer who bid over the phone, according to news reports. With additional fees, the total came to just over $6 million.
19 Portugal Place Cambridge 19 March ’53 My Dear Michael,
Jim Watson and I have probably made a most important discovery. We have built a model for the structure of de-oxy-ribose-nucleic-acid (read it carefully) called D.N.A. for short. You may remember that the genes of the chromosomes — which carry the hereditary factors — are made up of protein and D.N.A.
Our structure is very beautiful. D.N.A. can be thought of roughly as a very long chain with flat bits sticking out. The flat bits are called the “bases”. The formula is rather like this.
Now we have two of these chains winding round each other — each one is a helix — and the chain, made up of sugar and phosphorus, is on the outside, and the bases are all on the inside. I can’t draw it very well, but it looks like this
The model looks much nicer than this.
Now the exciting thing is that while these are 4 different bases, we find we can only put certain pairs of them together. Thee bases have names. They are Adenine, Guanine, Thymine & Cytosine. I will call them A, G, T and C. Now we find that the pairs we can make — which have one base from one chain joined to one base from another — are
only A with T and G with C.
Now on one chain, as far as we can see, one can have the bases in any order, but if their order is fixed, then the order on the other chain is also fixed. For example, suppose the first chain goes [points to string of letters on left], then the second must go [points to string of letters on right].
It is like a code. If you are given one set of letters you can write down the others.
Now we believe that the D.N.A. is a code. That is, the order of the bases (the letters) makes one gene different from another gene (just as one page of print is different from another). You can now see how Nature makes copies of the genes. Because if the two chains unwind into two separate chains, and if each chain then makes another chain come together on it, then because A always goes with T, and G with C, we shall get two copies where we had one before. For example:
In other words we think we have found the basic copying mechanism by which life comes from life. The beauty of our model is that the shape of it is such that only these pairs can go together, though they could pair up in other ways if they were floating about freely. You can understand that we are very excited. We have to have a letter off to Nature in a day or so. Read this carefully so that you understand it. When you come home we will show you the model.